PROJECT SUMMARY In pediatric cardiovascular surgery, no commercially available vascular conduit is capable of growing with the patient following implantation. This inability to grow with the patient is particularly relevant for newborns and young children because additional surgeries are required to replace the implanted conduit. In order to address this issue, PECA Labs has developed a novel cardiovascular conduit that can be expanded with a minimally invasive balloon catheter. This technology has been achieved by altering the properties of expanded- polytetrafluoroethylene (ePTFE) through a propriety manufacturing process. A prototype of PECA?s expandable conduit has successfully been developed, produced, and validated through benchtop, biocompatibility, and in vivo studies as well as successful achievement of CE Mark clearance for peripheral vascular use. Previous testing has illustrated the functionality of the proposed expandable ePTFE conduit (EEC), including resisting spontaneous expansion at normal pressures, yet being capable of expanding by dilation with a standard balloon catheter. Expansion to well over three times the original diameter has been demonstrated without compromising the mechanical strength. Furthermore, the applications of the technology are not limited to pediatric cardiovascular use, but also may provide significant benefits as a valved conduit and as a conduit for peripheral vascular reconstruction in adults. This significantly increases the market size and impact of the graft and with successful completion of benchtop, biocompatibility, and in vivo testing goals in Phase I. PECA Labs proposes the three specific aims to study the EEC in long term models ? central vascular reconstruction with growth, valved conduit reconstruction, and peripheral vascular reconstruction. Specific Aim 1: The goal of this aim is to study two-stage expansions as well as to compare expansions of EEC with and without the use of covered stents. Additionally, it is valuable to understand two stages of expansion, observe overall large animal health post-first expansion, and to assess compatibility of covered stents with the EEC. Specific Aim 2: The goal of this aim is to use a valved configuration of the EEC to create the first valved conduit capable of providing growth potential, achieved by expanding the valved conduit and observing its functionality in conjunction with a commercially-available transcatheter valve. This application has the potential to reduce the number of repeat open-heart surgeries by three or more over the lifetime of the child. The design of these versions is derived from a clinically-proven valved conduit design, including the proprietary intellectual property licensed by PECA Labs. Specific Aim 3: The goal of this aim is to understand the benefits of EEC in adult peripheral vascular reconstruction. This will be achieved by comparing the implanted EEC with a gold-standard vascular graft for peripheral reconstruction and assessing the benefits of expansion to lengthen the overall time for which a peripheral graft can last in adult patients.